Core C is the "Experimental Subjects" core and has three parts. Core C1 is the Human Subjects core where the primary function is the collection, storage, and analysis of medical and audiological information on human subjects (N=145 to 367) which covers the past ten years and the next five years. Core C1 also serves as a source of human subjects for Project 1 and 2. Core C2 is the Animal Subjects core where the purpose is to provide animals and physiological data for Project 3 and 4, as well as technical support for histology. Core C3 supports the collection and storage of human tissue from surgical, organ donor, transplant, and medical autopsy cases, and provides personnel support for histologic and other analyses of human tissue.